fix: mfsu global css priority

[sorrycc]

Checklist

• npm test passes
• tests are included
• documentation is changed or added
• commit message follows commit guidelines

Description of change

• close [Bug] mfsu css加载顺序问题 #6910

[codecov]

Codecov Report

Merging #6912 (569f61a) into master (33baf08) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##           master    #6912   +/-   ##
=======================================
  Coverage   78.96%   78.96%           
=======================================
  Files         170      170           
  Lines        4250     4250           
  Branches     1188     1188           
=======================================
  Hits         3356     3356           
  Misses        884      884           
  Partials       10       10           

Impacted Files	Coverage Δ
.../preset-built-in/src/plugins/features/globalCSS.ts	90.00% <0.00%> (ø)

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